Process of treating ores.



. To "all whom, it maye cem- N TE F T T Joint i nntfA-ngou' CANON CITY, coLoB Do.

? f Roc'Ess 0F. TREATING .0 ES. f 5 I smmemmmora g t-a bf Letters rele se. 7o7,io7, dated Au u t 1e, 1902.

imitati n filed March 23,1902. SerialNo. 100,457. mo g e m h t 1 Beit known that I, JOHN HERMAN, a citizen of the United States,residing at Canon City,-

rado,have invented new and useful Improve ments'in Processes of Treating Ores, of which the following is a specification;

q My invention relatesft'o theextractionof' A copperfrom ores; and zit consists in acertain vantages ofwhich will be fullyunderstood peculiar process, the novelty, utilityyand adfrom' the following description and claims;

Ifncarrying out onejembodimentof my-ing vention I roast sul-fid of-copper ore ata low --tain thefbest results. iThe jroasting of the heat and control thetemperatureso asto'obore [at a lovi heat forms sulfates of the copper Q andof'some of the iron present instead of Y so I or may not be entirely con'verted'into sulfate,

oxids of said metals, which would result'from the use of a high heat. Silver, if present, may

" I thisdependingonwhether orno the residue resulting from the leaching, presently described, is to be subjected to treatment. The "roasting of the sulfid oreat a low heat is also 1 desirable, because of theproduction of a large percentage of ferrouss'ulfate instead of a large treatment of carbonate or oxidores of copper,

stillhot, with water, .when-thecopperand iron a sulfates willdissolve; aswill also any silver ver is present, pass the solut on. through-or sulfate that has been formed. Ithen,-'if sil- 7 over copper turnings to effect the precipita tion' of the metallic silverand through or'over scrap-iron, whereby the metallic copper ispre= cipita-teds If no silver is-present or it is'not desired to recover the same, the solutionis passed through'the scrap-iron alone-"The use of the scrap-ironas alprecipitant for the of the processto convert the ferrous salts to copper increases the amount of [ferroussulk The said ferrous sulfate is highly desirable,

as before stated, for further operations. I t It isnecessary in order to fulfil the purpose in the county of Fremont and State of Colo the chlorid and to produce a. solution having I an excess of salts-7 e.,ia greater proportion "of. salt than ferrous chlorid -preferably two parts, by weight, of salt to onepart of ferrous 'chlorid. This is domain the present embodiment of the invention by adding sodium chlo rid to the solu tionieither'before or after precipitating the m'etalsfl Q o 1 7 'If the residue from-thefleaching contains gold, the same may be treated {by any of the ordinary modes witha view of saving the gold. It will also be observed that the-ores are ren- ,dered 'free millingand. that the processmay to savecopper and silvery beused toaccornplis'h this 'purpose,"as well as Theisolution of ferrouschloridand salt ob- 'tained in the manner described ishighly eff cient in dissolving copper'l and suchsilver as is in amenable compounds outjof carbonate and. oxid ores and'is'usedfor such purpose.

Then after lea'ching precipitation is carried;

on as before stated and with the same advan- I tage"-viz. the formation of ferrous sulfate. This orein mostcases is also rendered'free ordinarily practiced. t o I The reaction wherebyco per is dissolved -byferrous chl'oridand-salt is. h I2.Fe.Ol +3;CuQiflCuClefCdQlyl-FQOQ. The cupric chlorid soluble in watenfias is also cuprous chloridwheninjthepresen'ce of the other chloride. l w It will be readily appreciated that the embodinient of myinvention described" isma j te'rially advantageous, because instead of expensive chemicals it utilizes waste products, also-becausethe' solutionof ferrous chlorid and salt may be repeatedly used to advantage.

, In another and preferred embodiment of my. inventionI roasttheresidue from the first leaching with three(more.jor less) per cent. of common salt and atjahigher heat than in the first roasting,vbut not sufficiently'high to decompose the chlorids of copperand silver which are formed. In thisroastingof the residue the sulfur should be in excess of the copper, and,if'deficient,}theine'cessary sulfur is supplied by the additionof. fresh pyrites.

The roasted residue is then leached'with a salt solution which is'preferably quite strong,

after which the salt solution is mixed with the first-described leaching solution and passed with the same preferably, but not necessarily, through or over copper turnings to precipitate metallic silver, if present, and then through scrap-iron, the latter to precipitate metallic copper. If no silveris present, the mixed solutions are passed through the iron scraps alone, and in this connection I desire it understood that when preferable the solutions may be treated separatelyt'. e., may be passed through the copper turnings and the iron scraps or through the iron scraps alone-precedent to being mixed. When the roasting of the residue of the first leachingis resorted to, the conversion of the ferrous salts to the chlorid is effected, and the excess of salt in the solution of ferrous chlorid and salt is obtained by mixing the first-described leaching solution with that used in leaching the roasted residue. This solution of ferrous chlorid and salt is then used to dissolve copper and silver out of carbonate and oxid ores, after which leaching and precipitation are carried on in the same manner as in the first-described embodiment of the invention.

All of the advantages of the first-described embodiment of my invention are common to that last described, and the latter is also advantageous, because copper and silver which may have escaped the first treatment is saved by the second, and a larger percentage is saved by roasting twice than by roasting in either way alone. Moreover, less salt need be used than in roasting by the second mode only, and less obnoxious gases are formed.

In both embodiments of my invention the raw ore may be roasted once and salt added, whereby any ferrous sulfate is converted to ferrous chlorid. This renders soluble any copper oxid or carbonate originally present or formed in the roasting. The solution obtained by precipitating the copper may be also turned back over the residue.

Having described my invention, What I claim, and desire to secure by Letters Patent, 1s-

1. The process described which consists in roasting suliid-of-copper ore at a low heat to form sulfates of the copper and some of the iron present, and produce a large percentage of ferrous sulfate, leaching the roasted ore, precipitating the metallic copper, and adding salt to the leaching solution, before or after the precipitation of the metallic copper, whereby the ferrous salts in the solution are converted to the chloridand a solution having an excess of salt is produced, and the said solution is adapted to dissolve copper and silver out of carbonate and oxid ores.

2. The process described which consists in roasting sulfid-of-copper ore at a low heat to formsulfates of the copper and some of the iron present and producealarge percentage of ferrous sulfate, leaching the roasted ore, precipitating the metallic copper with iron scraps whereby the proportion of ferrous sulfate in increased, and adding salt to the leaching solution, before or after the precipitation of the metallic copper, whereby the ferrous salts in the solution are converted to the chlorid and a solution having an excess of salt is produced, and the said solution is adapted to dissolve copper and silver out of carbonate and oxid ores.

3. The process described which consists in roasting sulfid-of-copper ore at a low heat to form sulfates of the copper and some of the iron present, and produce a large percentage of ferrous sulfate, leaching the roasted ore, precipitating the metallic copper, adding salt to the leaching solution, before or after the precipitation of the metallic copper to convert the ferrous salts in the solution to the chlorid and a solution having an excess of saltis produced, leaching carbonate and oxid ores with the solution, and precipitating the metallic copper therefrom.

4. The process described which consists in roasting sulfid-of-copper ore at a low heat to form sulfates of the copper and some of the iron present, and produce a large percentage of ferrous sulfate, leaching the roasted ore, roasting the residue from the leaching in the presence of common salt, leaching the roasted residue with a salt solution, precipitating the metallic copper from the solutions, and coinmingling' the two solutions before or after the precipitation of the metallic copper for the purpose described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JOHN HERMAN.

\Vitnesses:

B. I. DAWSON, W. W. RICE. 

